Respiratory valve



FIG. 1 is a perspective view of the respiratory valve of the invention;

FIG. 2 is a rear elevation view of the respiratory valve of FIG. 1;

FIG. 3 is a front elevation view of the respiratory valve of FIG. 1;

FIG. 4 is a left side view of the respiratory valve of FIG. 1;

FIG. 5 is a right side view of the respiratory valve of FIG. 1;

FIG. 6 is a top plan view of the respiratory valve of FIG. 1; and,

FIG. 7 is a bottom plan view of the respiratory valve of FIG. 1.

The ornamental design for a respiratory valve, as shown and described.